This invention relates in general to locking apparatus, and in particular to apparatus for securing a doorknob against unauthorized entry.
The need to provide security for one's person and possessions has always been an important consideration, and rising crime statistics point out the need for even more concern for security. The desire for protection in one's home or business usually translates to the need for preventing or inhibiting unauthorized entry into a dwelling or other location, either to protect the occupants from intrusion or to secure the contents of the location.
Efforts to make a dwelling, office, or other location more secure usually include upgrading the locks on existing doors, or providing locks where none previously existed. Existing cylindrical locksets of the type having the lock cylinder mounted coaxially with the doorknob is typically one of the first items modified to increase security, because such knob locks are relatively easy to pick or to break for forced entry. As a practical matter, the existing knob locks are not actually replaced, but are supplemented by adding another lock to the door. While replacing or supplementing existing locks does increase security, that expedient becomes expensive where a dwelling or other location has several doors which must be protected. Moreover, that approach requires some skill and time at carpentry, and may be unfeasible where a person is a short-term occupant of the premises and does not want to spend money making permanent improvements.
In addition to increasing the security of external or outside doors, it is also desirable in many situations to lock one or more doors leading to a particular room in a dwelling or an office. Frequently, those room doors merely have a conventional doorknob latch and lack an existing lock of any kind, so that a particular room cannot be secured from unauthorized entry without spending the time and money to install a built-in door lock where none previously existed.
Various types of doorknob security devices are known in the art, which can be fastened in place to obscure or obstruct the keyhole of a conventional door knob lock. While the devices of the prior art may be effective for preventing unauthorized access to the keyhole, those devices generally leave at least part of the knob or its associated shaft accessible to damage by burglar tools such as a chisel or the like. The knob security devices of the art, moreover, tend to be relatively cumbersome and costly to manufacture. Furthermore, while such prior art devices may obstruct the keyhole of an existing knob lock, they offer no security for a door that does not have any existing knob lock.
Accordingly, it is an object of the present invention to provide improved doorknob lock apparatus.
It is another object of the present invention to provide doorknob lock apparatus which is readily adjustable to fit various sizes and styles of door knobs.
It is still another object of the present invention to provide doorknob lock apparatus which may be used to secure doorknobs lacking an existing knob lock.